From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756349Ab0EaIMT (ORCPT ); Mon, 31 May 2010 04:12:19 -0400 Received: from casper.infradead.org ([85.118.1.10]:59580 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751132Ab0EaIMS convert rfc822-to-8bit (ORCPT ); Mon, 31 May 2010 04:12:18 -0400 Subject: Re: [PATCH] tracing: Add task activate/deactivate tracepoints From: Peter Zijlstra To: Ingo Molnar Cc: Frederic Weisbecker , LKML , Steven Rostedt In-Reply-To: <20100531080049.GA435@elte.hu> References: <1275056762-13130-1-git-send-regression-fweisbec@gmail.com> <1275059710.27810.9624.camel@twins> <20100531080049.GA435@elte.hu> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Mon, 31 May 2010 10:12:24 +0200 Message-ID: <1275293544.27810.21478.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2010-05-31 at 10:00 +0200, Ingo Molnar wrote: > > > > NAK, aside from a few corner cases wakeup and sleep are the important > > points. > > > > The activate and deactivate functions are implementation details. > > Frederic, can you show us a concrete example of where we dont know what is > going on due to inadequate instrumentation? Can we fix that be extending the > existing tracepoints? Right, so a few of those corner cases I mentioned above are things like re-nice, PI-boosts etc.. Those use deactivate, modify task-state, activate cycles. so if you want to see those, we can add an explicit tracepoint for those actions. An explicit nice/PI-boost tracepoint is much clearer than trying to figure out wth the deactivate/activate cycle was for.